Air-brake



L. L. BONHAM.

AIR BRAKE.

APPLICATION FILED MAYIfi, I919.

1,359,664, 4 Patented Nov. 23, 1920.

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AIR BRAKE.

APPLICATION FILED MAYI6, I919.

Patented Nov. 23, 1920.

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AIR BRAKE.

APPLICATION FILED MAYI6,1919.

1,359' 664, Patented Nov. 23, 1920.

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AIR BRAKE.

APPLICATION FILED MAYIG, 1919.

1 59,664, Patented Nov. 23, 1920.

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L. L. BONHAM.

AIR BRAKE.

APPLICATION FILED MAYIG. 19x9.

Patented Nov. 23', 1920.

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LWMTED ETATES PAT EN? @FEQE.

AIR-BRAKE.

Application filed May 16,

To all whom it may concern.

Be it lmown that I, LUTHER LAFAYETTE Born-mar, a citizen of the United States, residing at Knoxville, in the county of Knox and State 01"- Tennessee, have invented a new and useful Improvement in Air-Brakes, of which the following is a specification, reference being had to the accompanying drawing.

My invention relates particularly to airbrake equipment to be used on standard railway trains.

The object of the improvement is to provide for safely and practically effecting a more rapid discharge or exhaust of air from the brake pipe of the train when the engineers automatic brake valve is put into service position, in order that service application of the bralres'may be made throughout the train in less time than is now required. for this purpose. Under present practice, during such exhausting of air from the brake pipe when the automatic brake valve is in service position, it requires a greater length of time to exhaust the air from the brake pipe than is required with my inven tion. As is known to those familiar with this art, such emergency application is apt to be made through a quick or abrupt transmission of pressure resembling a positive or clearly defined pulsation or throb. To illustrate, it is known that the sudden opening and closing of a quarter inch port on the brake pipe of the train would cause such a pulsation of sutlicient force to lead to emer gency application of the brakes. Hence it has been recognized as necessary to so con trol air above the equalizing piston and also below that piston as to avoid the transmission of pulsation or shock from the brake pipe into the triple valves and into the distributing valve or automatic control valve, it one is used. Under the construction heretofore in use the effecting of a graduation or even flow of exhaust can be accomplished only through restraining the flow. This has necessitated limiting the size of the port in the service-exhaust fitting of the automatic brake valve, in order to graduateor limit the l How of air from the brake pipe to the atmosphere; and this has led to making the valve leading from the lower side of the equalizing piston of form adapted to graduate or i limit flow of air so as to prevent such abrupt change of velocity of air flowwhen the valve in raised will a well defined Speoification of Letters Patent.

IPatented Nov. 23, 1920.

Serial No. 297,479.

throb or pulsation through the brake pipe. This slow exhaustion delays the service ap plication of the brakes.

y my improvement I provide an enlarged volume of air freely flowing from the brake pipev into the chamber below the equalizing piston so that abrupt change of density of air in said chamber is avoided. In other words, such air. is made of sufficient volume to cause a well graduated change of density in said chamber due to flow of air outward through the port opening of the service-exhaust fitting.

Having thus provided for reduction of tendency to abrupt or spasmodicchange of density in said chamber, the way has been.

prepared for safely and practically enlarging said exhaust port and enlarging the valve which permits air to flow to said port.

In the accompanying drawings,

Figure 1 is a diagrammatic view illustrating portions of an air-brake equipment for a railway train; a

Fig. 2 is an elevation of the automatic brake valve which forms a part of the equipment shown by Fig. 1;

Fig. 3 is a plan of the same automatic brake-valve i Fig. 4: is a bottom view of the same valve;

Fig. 5 is an upright section on the line, 5 5, of Figs. 3 and 4-,looking in the direction of the arrow;

Fig. 6 is an upright section on the line, 6-6, of Figs. 3 and 4, looking in the direction of the arrow.

Referring first to Fig. 1, A is the automatic brake valve of a form of Westinghouse air-brake equipment for trains. B is the independent brake valve. C is the distributing valve. D is a reducing valve. E is a feed valve. F and G are gages. H is the main reservoir pipe. I is a pipe leading from the main reservoir pipe to the gage, F. J is a feed valve pipe leading from the feed valve, E, into the automatic brake valve. K is the governor pipe leading from the, automatic brake valve to the pump governor (not shown). L is the release pipe leading from the air-brake valve to the independent brake valve, B. M is theapplication cylinder pipe leading from the valve, A,

to the valve, B, and the valve, C. N is a gage pipe leading from the valve, A, to the gage, F, and to the equalizing reservoir, 0.. is a pipe leading from the pipe, Q, to the gage, Q, is thebrake pipe. is a pipe leading from the distributing valve, to the brake pipe. S is a release pipe joining the valve, B, and the valve, C. T is the brake cylinder pipe. This connects with the distributing valve, (3. U is a gage pipe which conveys air from the brake cyllVhile the bushing, i1 and the stem, A,

and the exhaust, A", are arranged relatively as has been done heretofore, I have increased the cross sectional area of the stem, A*, and of the interior of said bushing and of said fitting. This has been made possible by my introduction of another feature which will be described farther on.

In the standard form heretofore in use, the service-exhaust fitting, A, has had a port opening of g 01": an inch. I haveincreased this port opening to The obgect in using alarger port opening for the fittlng, A ,is to exhaust the air from the brake plpe more rapidly than can be done wlth the or dinary equipment now in use. This faster exhaustion leads to a speedier service application of brakes throughout the train.

But, heretofore such rapid discharge of air from the fitting, A, has been impracticable for the reason that a more rapid exhaust than was permitted by the small port (5 2 of an inch) would lead to en1e r gency application of the engme and tra n brakes while the engineers automatlc brake valve was set in service position. When, according to present practice, a partial or full service application of locomotive and train brakes isdesired, the automatic brake valve is put into service pos tion. Then, in the well-known manner, air is exhausted from the chamber, A, above the piston, A and from the equalizing reservoir, O, which communicates with said chamber through the pipe, N. The automatic brake valve is then placed into lap position. For a full service application of the brakes, when the brake pipe pressure is pounds, 20 pounds of air is exhausted from the chamber, A and reservoir, 0. Theexhausting of the air from the chamber,

A permits the piston, A to rise on acthe remaining pressure in the chamber, A to againdrivethe piston, A down to normal position, the position in which the valve, A, is closed.

As has alread been stated, it is well-known to those who are familiar with this art, that emergency application is liable to be made whenever there is a quick or abrupt transmission of pressure, resembling a positive or clearly defined pulsation, through the brake pipe.

To avoid quick or abrupt changes oi pressure due to exhaustion from the chamber, A elow the piston, A I have provided on or in connection with the brake pipe, Q, an air reservoir, Q which will contain such a r g uantity of air near the automatic valve as to cause such a nearly uniform delivery of air through the upper end oi" the brake pipe, (has will prevent a quick or abrupt varia tion in pressure in the chamber, Ai. In Fig. l of the drawings, the reservoir, Q, is attached to the pipe, Q, by means of a branch, Q}. In Fig. 5 the reservoir, Q is directly on the pipe, Q, a gap being formed in the pipe and the ends of the pipe being tapped into the ends of the reservoir. As soon as the reduction'of air pressure above the piston, A begins, the piston is lifted by the greater air pressure below the piston. Thus the valve below the piston is opened and air exhausted through the valve and the port oi theexhaust fitting, A This exhausting continues until the pressure below the piston becomes equal to the pressure above the piston. That requires a pressure reduction in the entire length of the brake pipe. The

amountot air requiredto be thus exhausted through the exhaust'fitting to produce bal ance of pressure above and below the piston increases with increase in the length of the train; and since the length of trains is being increased in practice, it becomes increasingly important-to effect a more rapid exhaust from the exhaust fitting of the automatic brake valve. In shop tests of my improved apparatus (inwhich the valve, A, and the exhaust port were enlarged as above described), I connected a triple valve to the brake pipe between the reservoir, Q and the automatic brake valve. Then setting the automatlc brake valve to service position resulted in putting the triple valve into service position and not into emergency position.

That indicated that thelarger volume of air in the reservoir, Q}, supplies air into the automatic brake valve in such quantity as to cause a graduated flow through the exhaust port, whereby the forming of pulsation is entirely or substantially prevented. l deem it probable also that the air in the reservoir, Q}, serves as a cushion or shock absorber for neutralizing such. reduced puldo extend from the automatic brake valve into said reservoir; so that my improved apparatus is adapted (1) to prevent or reduce the forming of pulsation, and (2) to neutralize such pulsation as is formed and extends into the reservoir, Q

1 claim as my invention,

1. In an air brake equipment, the combi nation with the automatic brake valve having an enlarged exhaust port and the brake pipe leading into the chamber below the equalizing piston, of an air reservoir in communication with the brake pipe in position to readily deliver air into said chamber when the exhaust valve of the automatic brake valve is open, in order that during service application abrupt changes in air density in said chamber may be prevented and'in order that the transmission of shocks or pulsations through the brake pipe may be prevented, substantially as described;

2. In an air brake equipment, the combination With the automatic brake valve having an enlarged exhaust port, of a brake pipe structure leading into the chamber be low the equalizing piston and being of sufi'icient interior capacity to contain an enlarged and sufiicient volume of air to cause ready delivery of air into said chamber when the exhaust valve of the automatic brake valve is open, in order that during service application abrupt changes in air density in said chamber may be prevented and the transmission of shocks or pulsations through the brake pipe may be prevented, substantially as described.

In testimony whereof I have signed my name, this 3rd day of May, in the year one thousand nine hundred and nineteen.

LUTHER L. BONHAM. 

